This invention relates to a solar collector and more particularly to a system for sealing a glass panel or the like to the sides of a solar collector case or housing.
Solar collectors may take a variety of configurations, but a typical collector will include a case or housing in which is positioned a heat collecting or absorbing plate, conduits placed in contact with the plate for carrying a heat transfer fluid, and headers for distributing fluid to the conduits and receiving fluid therefrom. The top side of the housing is covered by one or more glass panels for allowing sunlight to pass therethrough onto the heat absorbing plate. It is desired that such a glass panel be effectively sealed in the housing so that the panel can serve both to prevent the entry of moisture and to retain within the housing air which is heated by the sunlight. Additionally, it is desired that such glass panels be readily removable to allow access to the interior of the housing.
Caulking has been used in the past to obtain a weather-tight seal between the glass panel and side walls of a solar collector housing, but such a seal is difficult and time-consuming to install and, when the glass panel is removed, the seal is destroyed and must be reinstalled when the panel is put back in place. Gaskets of various types have also been used to seal glass panels in collector housings, with some type of metal cap strip being used to apply pressure to the gaskets. The cap strips are generally held in place by spaced apart screws or bolts, and such spacing typically results in the sealing pressure being uneven around the perimeter of the housing ("scalloping" of the seal). A number of arrangements have been proposed which would not use screws or bolts to seal glass panels in collector housings, but these arrangements are oftentimes complicated in design, require a multiplicity of separate elements, and are expensive to manufacture. Exemplary prior art solar collectors and sealing arrangements are disclosed in U.S. Pat. Nos. 4,206,748, 4,269,173, 4,231,204 and 4,266,383.